The present invention relates to valves in general, and more particularly to improvements in bypass valves for use in pumping and/or heating systems. Still more particularly, the invention relates to improvements in bypass valves of the type wherein a relatively large valving element is coupled with a smaller valving element.
Bypass valves are utilized in a variety of fluid conveying systems. For example, a bypass valve can be used to direct some fluid from the pump discharge nozzle directly to the suction nozzle of the pump when it is undesirable or impractical to operate the pump at a greatly reduced rate of flow. Such valves are equally useful to prevent overheating of pumped fluid at part loads, for control reasons and/or for axial thrust compensation. Best known purposes of bypass valves are to relieve a pump and/or to insure the circulation of a fluid at a minimum rate regardless of fluctuations of the requirements of the consuming system or systems. For example, a relief or bypass port will be opened in automatic response to rising fluid pressure when the flow of fluid along the main path (i.e., from the inlet to the main outlet of a valve) is throttled or interrupted.